The long-term goal of the Clinical Core is to provide the expertise and infrastructure to assure the completion of all of the patient-based research studies proposed in this SPORE grant. The core goals will be achieved through accomplishing the following aims: 1. Assess the status of APC gene and ODC gene promoter in patients with colorectal adenomas participating in chemoprevention trials (Principal Investigator-David Alberts, M.D.). 2. Evaluate clinical activity of cycloxygenase inhibitor celecoxib in reversing Barrett?s esophagus as premalignant lesion in a phase II clinical trial (Principal Investigator-Harinder Garewal, M.D.). 3. Conduct pilot studies of vaccination with dendritic cells expressing MUC1-fusion proteins in patients with gastrointestinal malignancies (Principal Investigator-Evan Hersh, M.D.). 4. Evaluate new thioredoxin-1 inhibitor PX-12 in a phase II clinical trial in patients with colorectal cancer (Principal Investigator-Tomislav Dragovich, M.D., Ph.D.) 5. Evaluate clinical activity of C-myc inhibitors in patients with pancreatic and colorectal cancers (Principal Investigator-Daniel D. Von Hoff M.D.). 6. Design and conduct clinical trials with new target-based treatments validated through our developmental projects (for example-new urokinase inhibitors, hypomethylating agents). We intend to accomplish these aims by assembling a team of expert clinical investigators and clinical research staff that will complement already existing clinical research effort here at the University of Arizona/Arizona Cancer Center. This resource core will be devoted to development and evaluation of new treatment approaches for patients with gastrointestinal malignancies. The core will supervise design and conduct of clinical trials for patients with gastrointestinal cancer, facilitate acquisition of pharmacokinetic and pharmacodynamic data, and supervise and facilitate acquisition of biologic samples from patients participating in clinical trials.